Background: This study investigated the outcomes after radical hysterectomy according to tumor size divided by 2-cm interval in patients with International Federation of Obstetrics and Gynecology stage IA2–IIA cervical cancer.Patients and methods: A total of 1415 patients were eligible for participation in the study and were retrospectively analyzed. Patients were divided into four groups according to tumor size (i.e. ≤2, 2–4, 4–6 and >6 cm). The relationships between tumor size and other clinicopathologic risk factors, the probability of adjuvant therapy, survival parameters, recurrence-free survival (RFS) and overall survival (OS) were analyzed.Results: The incidence of intermediate- and high-risk factors gradually increased with increasing tumor size. Adjuvant therapy was required in 13.6%, 34.0%, 56.7% and 92.9% of patients with tumor sizes of ≤2, 2–4, 4–6 and >6 cm, respectively (P < 0.001). The risks of recurrence and death gradually increased with increasing tumor size, after adjusting for other significant prognostic factors in multivariate analysis (P < 0.001 and < 0.001, respectively). Even in patients with no intermediate- or high-risk factors, tumor size was a significant predictor of RFS and OS (P < 0.001 and < 0.001, respectively). Immediate surgical parameters did not significantly differ according to tumor size.Conclusions: Tumor size divided by a 2-cm interval was an independent prognostic factor and correlated well with other risk factors and with the need for adjuvant therapy.